Honolulu Star-Advertiser © Susan Scott
November 17, 2018
Back when we moored our sailboat Honu on the outer row of the Ala Wai Boat Harbor, every walk down the pier was a potential adventure. Over the years, octopus, eagle rays, mantis shrimp, jellyfish, jacks and dozens of other marine animals entertained me as I strolled past the boats.
The same is true of Honu’s current berth in Townsville, Australia. One evening last week as we relaxed in the cockpit sipping tea, a loud splash caused us to jump up.
An adult archerfish in Breakwater Marina, Townsville, Australia.
©2018 Susan Scott
We’ve been around boats long enough to recognize the sound of fish jumping, and this was no fish. We were sure a person had fallen in the water, but as we gaped at the disturbed surface, no one thrashed or swam.
Because on a previous visit the marina had posted signs on the gates warning that a saltwater crocodile had been spotted among the boats, we wondered if the big splash had been a croc.
“We get sharks and rays jumping in here,” the marina manager said with a shrug. “But a salty is a good guess, too.”
Later I found a smaller splash equally thrilling.
The Townsville marina hosts an abundance of archerfish, carnivorous species that hover almost motionless near the water’s surface under walkways to the docks.
The spotted, 10- to 12-inch archerfish are down there in the shadows waiting for an unsuspecting spider to crawl, or a flying insect to land, on the walkway’s supports. When that happens the fish shoots it down with its built-in super soaker.
Archerfish inhabit tropical waters protected from wind and waves, such as rivers, estuaries and marinas. The fish aren’t found in Hawaii, but other parts of the Pacific host seven species of these oddly shaped fish that have upward-pointing mouths.
Because mangrove tree roots and man-made support structures provide habitat for bugs, these are favorite archerfish hangouts.
Each archerfish has a groove on the roof of its mouth. When the fish spots an insect within range, it closes its gill covers, presses its tongue against the groove and squirts a powerful stream of water at its prey. The mouth rises above the water, but the fish’s eyes remain below.
Young archerfish sometimes miss their targets, but they soon learn to judge distances, as well as the refraction of light against the water, and perfect their aim.
I was disappointed that no marina archerfish shot down bugs while I watched, but later, during a visit to Townsville’s outstanding aquarium (called Reef HQ) a large archerfish granted my wish. As I rested my hand on a wooden support of an exhibit, the fish squirted my thumb.
Both here and abroad, I often find joy in marine animals without even getting wet. Except, occasionally, for my thumb.
P.S. The Waikiki Aquarium features archerfish, well worth a visit.